Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L23/00—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers
  • C08L23/02—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers not modified by chemical after-treatment
  • C08L23/10—Homopolymers or copolymers of propene
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L23/00—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers
  • C08L23/02—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers not modified by chemical after-treatment
  • C08L23/16—Elastomeric ethene-propene or ethene-propene-diene copolymers, e.g. EPR and EPDM rubbers
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L2205/00—Polymer mixtures characterised by other features
  • C08L2205/02—Polymer mixtures characterised by other features containing two or more polymers of the same C08L -group
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L23/00—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers
  • C08L23/02—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers not modified by chemical after-treatment
  • C08L23/10—Homopolymers or copolymers of propene
  • C08L23/12—Polypropene
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L2312/00—Crosslinking
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L91/00—Compositions of oils, fats or waxes; Compositions of derivatives thereof

Definitions

• the present invention relates to a plastoelastomeric polyolefinic compositions, consisting of mixes of at least partially vulcanized EP or EPDM rubber with at least an olefinic plastomeric thermoplastic polymer, and obtained by dynamic vulcanization of the corresponding mixes containing the rubber in the non-vulcanized state.
• compositions based on thermoplastic polymers and vulcanized rubbers using a dynamic vulcanization method is known in the art and is described in particular in U.S. Pat. Nos. 3,578,643; 3,862,106; 3,037,954 and 3,806,558.
• vulcanization of the elastomeric component is made to occur during the step of mixing or mastication with a plastomeric polymer in the molten state, using cross-linking agents, which are usually of the conventional type, such as e.g. peroxides, azide compounds, mixtures of sulphur with zinc oxide, substituted ureas, thiocarbamates, etc. If in the so-treated mixture there is a sufficient amount of plastomeric polymer, the composition, on conclusion of the vulcanization of the elastomeric component, retains good processability characteristics in hot conditions also if it contains high proportions of vulcanized elastomer.
• cross-linking agents which are usually of the conventional type, such as e.g. peroxides, azide compounds, mixtures of sulphur with zinc oxide, substituted ureas, thiocarbamates, etc.
• polyolefinic plastoelastomeric compositions are obtained using dynamic vulcanization methods. These utilize, as a cross-linking agent, a halogenated phenolic resin, or a phenolic resin which are not halogenated but are associated with halogen donors, in combination with a metal oxide (activator).
• the mix of EPDM rubber and olefinic polymer wherein the phenolic resin content ranges from 5 to 20% for the rubber, is subjected to mastication at a temperature sufficient to melt the olefinic polymer. Then the activator is added and mastication is continued at a temperature at which the elastomeric component cross-linking occurs.
• the metal oxide in particular the zinc oxide, favors in this case the complete cross-linking of the elastomer, which is one of the objects of the process of the patent.
• the products obtained according to the above-cited processes exhibit good elastomeric characteristics at room temperature.
• these characteristics in particular the compression set values, decay as the temperature rises, which jeopardizes the practical utilization of the products above the melting point of the plastomer.
• thermoplastic elastomers by subjecting a blend of an EPDM interpolymer with polypropylene and substantial amounts of polyethylene to a cross-linking reaction using free radical generating agents, while submitted to hot working.
• polyethylene is preferentially cross-linked and grafted to the EPDM interpolymer, thereby protecting polypropylene from radical attack, degradation and cross-linking or grafting reactions.
• the product thus obtained possesses improved molding characteristics, but exceedingly loose elastic properties such as elongation as break tension set and compression set, especially at high temperatures.
• compositions which represent one of the objects of the present invention, comprise an intimate mixture of the following components, in the indicated percentages by weight, referred to the whole mixture:
• cross-linked or non cross-linked polyethylene can be present in the composition in amounts lower than 4% by weight on the weight of the polymer composition.
• compositions may optionally contain also inorganic and/or organic non polymeric products such as ZnO, SiO 2 , TiO 2 , kaolin, carbon black, stabilizers, anti-ageing agents, catalysts, accelerators, cross-linking coadjuvants or decomposition products thereof.
• inorganic and/or organic non polymeric products such as ZnO, SiO 2 , TiO 2 , kaolin, carbon black, stabilizers, anti-ageing agents, catalysts, accelerators, cross-linking coadjuvants or decomposition products thereof.
• the polypropylene as per point (A) may be a homopolymer, or a copolymer of propylene with up to 10% by weight of copolymerized ethylene.
• the copolymers and terpolymers defined at point (B) may contain from 25 to 60% by weight, but preferably from 30 to 45% by weight, of propylene, and from 0 to 5% by weight of units deriving from one or more conjugated or non-conjugated dienic monomers, such as for example, indene, 1,3-butadiene, 1,4-hexadiene, norbornadiene, ethylidenenorbornene, cyclcopentadiene.
• conjugated or non-conjugated dienic monomers such as for example, indene, 1,3-butadiene, 1,4-hexadiene, norbornadiene, ethylidenenorbornene, cyclcopentadiene.
• Ziegler catalysts are the catalysts prepared by contacting a compound of a metal belonging to group IVa, Va, VIa or VIIa of the Mendelejeff periodic system, such as e.g. a Ti, V or Cr halide with organometallic compounds of a metal of group I, II or III of the periodic table of the elements containing at least a metal-carbon bond, alkyls such as e.g. Al alkyls and Al alkyl halides.
• a compound of a metal belonging to group IVa, Va, VIa or VIIa of the Mendelejeff periodic system such as e.g. a Ti, V or Cr halide
• organometallic compounds of a metal of group I, II or III of the periodic table of the elements containing at least a metal-carbon bond alkyls such as e.g. Al alkyls and Al alkyl halides.
• the molecular weight of the elastomeric copolymer or terpolymer exhibits a rather high value, corresponding to
• propylene can enter the polymeric chain according to primary or secondary insertions, as is described for example by I. Pasquon and U. Giannini in "Catalysts Science & Technology" vol. 6, pages 65-159, J. R. Anderson & N. Doudart, Springer Verlag, Berlin (1984), hereby incorporated by reference.
• Propylene enchainment inversion means the insertion variation (from primary to secondary) that the propylene molecule may exhibit in the macromolecule.
• DMSO dimethyl sulphoxide
• parameters X 2 and X 4 represent the fraction of methylene sequences, having 2 and 4 uninterrupted methylene groups between two consecutive methyl or methine groups in the polymeric chain, regarding the total of uninterrupted methylene sequences determined by 13 C NMR.
• the value of the fraction is calculated according to the method described by J. C. Randall in "Macromolecules" 11, 33 (1978).
• Copolymers and terpolymers endowed with such characteristics are known. They are preparable by polymerization of the corresponding monomer mixtures in the presence of Ziegler catalysts based on titanium compounds optionally carried on magnesium halide, and on aluminum organometal compounds. Catalysts of this kind are described for example in U.S. Pat. No. 4,013,823, in published European patent application No. 202,550, in Italian patent No. 117,340 and in Italian patent applications Nos. 20,203 A/81, 20,386 A/85, 21,872 A/86, 21,510 A/87 in the name of the applicant hereof, all hereby incorporated by reference.
• the polymeric product which is insoluble in xylene at 135° C. and which constitutes component (C) of the compositions according to the invention, substantially comprises the products derived from the cross-linking of components (A) and (B), and possibly the grafting products of components (A) and (B), either cross-linked or not cross-linked, the ones on the others.
• the polypropylene content in the component (C) ranges from 5 to 20% and preferably from 10 to 15% by weight referred to the weight of the whole composition.
• Component (D) consists of an oil of the type which is usually utilized to carry out the extension of rubbers in general, and it can be an aromatic, naphthenic or, preferably, paraffinic oil.
• the elastomeric phase appears to be dispersed in the continuous plastomeric phase in the form of particles of sizes not greater than 10 microns, with at least 50% thereof having a size lower than 5 microns.
• the plastoelastomeric compositions which are one of the objects of the present invention, are preparable by subjecting to mastication or to other shearing stresses, in the presence of a peroxide cross-linking agent and of particular cross-linking coadjuvants, as defined hereinafter, a polymeric mixture comprising from 20 to 80% by weight, but preferably from 60 to 25% by weight of polypropylene and from 80 to 20% by weight, but preferably from 40 to 75% by weight of an ethylene-propylene elastomeric copolymer or of an ethylene-propylenediene elastomeric terpolymer, at a temperature which is sufficient to melt the polypropylene and at which the cross-linking of about 50-85% by weight of the starting elastomer amount occurs.
• amounts of polyethylene lower than 4% by weight on the weight of the polymeric mixture can be present therein.
• cross-linking comprises both the actual cross-linking or vulcanization reaction of the elastomer.
• the reaction which may lead to the grafting of the cross-linked or non cross-linked elastomer on the polypropylene (or plastomeric phase) as a consequence of the reaction promoted by the cross-linking system utilized.
• cross-linking agents use is made of organic peroxides, preferably of those which exhibit a halving time of 10-200 seconds at a temperature ranging from 100° C. to 240° C., at which the vulcanization reaction is made to occur.
• peroxides examples include dicumyl peroxide, ⁇ , ⁇ 'bis(t.butylperoxy)-m- and/or -p-diisopropylbenzene, and 1,1-di-t.butylperoxide-3,5,5-trimethylcyclohexane.
• the peroxide amount utilized in the vulcanization generally ranges from 0.1 to 10% by weight, but preferably from 0.2 to 5% by weight calculated on the elastomeric component.
• the coadjuvants are utilized in amounts corresponding to about 5-60% by weight, but preferably to about 10-30% by weight for the utilized peroxide.
• furan derivatives according to formulas (I) and (II) utilizable for the purposes of the present invention are 1,5-difurfuryl-1,4-pentadiene-3-one and difurfuralaldazine.
• ⁇ -(alpha-furyl)-acrolein 5-(alpha-furyl)-pentadienal; ⁇ -(alpha-furyl)acrylamide; ⁇ -(alpha-furyl)acrylonitrile; ⁇ -(alpha-furyl) acrylic acid and esters thereof; bis-furfuryldene acetone; alpha-ethyl- ⁇ -(alpha) acrolein; the esters of the furfurylidene malonic acid.
• the products obtained from the condensation of ⁇ -(alpha-furyl acrolein) with cyclic ketones are described in "Berichte," 76, 676 (1943), hereby incorporated by reference.
• Another object of the present invention is a process for preparing plastoelastomeric polyolefinic compositions, which comprises, in order, the following operative steps:
• a paraffin extender oil in an amount ranging from 6 to 100 parts by weight and preferably from 20 to 80 parts by weight for 100 parts of the product.
• the mixture elastomeric product specified under (b) contains from 25 to 60%, preferably from 30 to 45% by weight of copolymerized propylene, and from 0 to 5% by weight of units deriving from one or more conjugated or non-conjugated dienic monomers as mentioned hereinbefore. It may have a molecular weight corresponding to
• the molecular weight of the elastomeric component corresponds to
• such component is preferably selected from ethylene/propylene/(diene) copolymers and terpolymers, in the structure of which head-to-head, tail-to-tail inversions of the propylenic unit, as mentioned hereinafter, are substantially missing.
• the copolymers and terpolymers are selected from the one which exhibit values of the R 1 ⁇ R 2 product higher than 2, and a wide distribution of the molecular weights expressed by values of the Mw/Mn ratio equal at least to 6, and preferably ranging from 10 to 15.
• the R 1 ⁇ R 2 represents, as is known, the product between the reactivity ratios of ethylene (R 1 ) and of propylene (R 2 ).
• the product is calculated from the sequence distribution in such copolymers and terpolymers through 13 C NMR analysis, according to known methods.
• vulcanization co-agents or coadjuvants for example liquid polybutadiene, triallyl cyanurate
• thermal stabilizers, antioxidants, mineral fillers, dyes may be added to the mixture of reaction components from (a) to (d) cited above.
• the propylene amount belonging to the product which is insoluble in xylene at 135° C., accounts for 20 to 70%, preferably from 30 to 50% by weight of the polypropylene contained in the starting mixture subjected to cross-linking.
• the elastomeric copolymer or terpolymer belonging to the insoluble product amounts to 50-85%, but preferably to 70-85% by weight of the copolymer or terpolymer contained in the starting mixture.
• the mixture was then discharged and granulated by using a Bandera single-screw extruder.
• the granules were then sent to a laboratory two-screw extruder produced by A.P.V. having a length/diameter (L/D) ratio equal to 25 and a diameter of 127 mm, equipped with conveyance and masticating elements, by means of which a residence time of 60 seconds was obtained, and which was operating at a temperature from 160° C. to 240° C.
• thermoplastic composition The analysis gave the following results, expressed in % by weight on the thermoplastic composition:
• the elastomeric phase appears to be highly dispersed with particle size lower than 10 microns, at least 50% thereof having a size lower than 5 microns.
• the autoclave was brought to a temperature of 60° C. and propylene, withdrawn from a proper cylinder thermoregulated at 40° C., was introduced under stirring up to a pressure of 3.5 atm. While maintaining both constant temperature and pressure, propylene was fed till about 1300 g of polypropylene were produced. Degassing was then carried out to remove the solvent and the unreacted propylene, bringing the temperature in the autoclave again to 20° C. While maintaining the polymer mass under stirring and operating at a temperature of 20° C., the autoclave was fed with a 50/50 by weight mixture of ethylene/propylene withdrawn from cylinders thermoregulated at 40° C., till a pressure of 9.5 atm. was reached.
• the synthesis product was converted to pellets using a head-cut single-screw extruder, to facilitate the product feeding to the APV extruder of the preceding example.
• test was conducted as is described in example 1 as regards both the arrangement in the APV extruder and the addition of cross-linking agents, co-agents, polypropylene and extender oil.
• the particle size of the dispersed elastomeric phase turned out to be lower than 10 microns, with at least 50% of the particles having a size lower than 5 microns.
• the size of 5 of the dispersed elastomeric particles was lower than 10 microns.
• the size of the elastomeric dispersed particles was lower than 10 microns, with more than 50% of the particles having a size lower than 5 microns.
• cross-linking coadjuvant 1.5-difurfuryl-1,4-pentadien-3-one in an amount equal to 0.3% by weight referred to the mix of the two polymers.
• thermoplastic composition The analysis of the obtained product gave the following results expressed as % by weight of the thermoplastic composition:
• the size of the dispersed elastomeric particles turned out to be lower than 10 microns, at least 50% of the particles having a size lower than 5 microns.
• the polymer so obtained had a propylene content equal to 60.5% by weight.
• the copolymeric component of the product so obtained was composed of an ethylene/propylene copolymer having a propylene content of 47% and exhibiting the following characteristics:
• the synthesis product was transformed to pellets by means of a head-cut, single-screw extruder, to favor the feeding to the APV extruder.
• test was conducted as is described in example 5 for both the APV extruder and the addition of cross-linking agents, co-agents, polypropylene and oil.
• thermoplastic composition The analysis gave the following results, expressed in % by weight of the thermoplastic composition:
• the dispersed elastomeric particle size was lower than 10 microns, with more than 50% of the particles having a size lower than 5 microns.
• the dispersed elastomeric particle size was not higher than 10 microns, with at least 50% of the particles having a size lower than 5 microns.
• Example 5 was repeated, with the only difference that an ethylene/propylene/1,4-butadiene terpolymer prepared by means of a Ti-catalyst similar to the one described in example 1 of Italian patent application No. 21,510 A/87 in the name of the Applicant hereof, was utilized as an elastomeric component, using aluminum triisobutyl as a co-catalyst, and having the following characteristics:
• the size of the elastomeric dispersed particles was lower than 10 microns, with at least 50% of the particles having a size lower than 5 microns.
• Example 8 was repeated, but without using 1,5-difurfuryl-1,4-pentadien-3-one as a vulcanization coadjuvant.
• the analysis of the composition after cross-linking gave the following results, expressed in % by weight:
• Example 1 was repeated, using, instead of di-furfural aldazine, 0.4% by weight of triallyl cyanurate as a cross-linking co-agent.

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• 1988
  • 1988-09-13 IT IT8821906A patent/IT1227341B/it active
• 1989
  • 1989-09-08 ZA ZA896888A patent/ZA896888B/xx unknown
  • 1989-09-11 RO RO141577A patent/RO105577B1/ro unknown
  • 1989-09-12 ES ES89116877T patent/ES2071634T3/es not_active Expired - Lifetime
  • 1989-09-12 BR BR898904592A patent/BR8904592A/pt not_active IP Right Cessation
  • 1989-09-12 KR KR1019890013382A patent/KR0145727B1/ko not_active IP Right Cessation
  • 1989-09-12 EP EP89116877A patent/EP0361205B1/en not_active Expired - Lifetime
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  • 1989-09-13 JP JP1238333A patent/JP3061816B2/ja not_active Expired - Fee Related
  • 1989-09-13 US US07/406,971 patent/US4963612A/en not_active Expired - Lifetime
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  • 1989-09-13 CS CS895281A patent/CS276499B6/cs not_active IP Right Cessation
• 1990
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